Machine Guarding Calculator

A hand or finger has to physically reach through the opening to contact the hazard, and the farther away that hazard is, the more of the hand's reach is used up just closing the distance -- reducing how far it can still probe once past the guard. This calculator's max safe opening table reflects OSHA Table O-10's relationship: it steps up from as small as 0.25 inches at very close range (guard distance of 1.5 inches or less) to 2.125 inches once the guard sits 17.5+ inches from the hazard, up to this calculator's 24-inch input maximum.

It calculates how far away a guard has to be positioned so that a hand moving toward the hazard at a standard assumed speed of 63 inches per second cannot reach the danger point before the machine has completed an emergency stop. The formula is distance = 63 x stopping time in seconds -- a machine that takes longer to stop needs its guard placed correspondingly farther away.

Not necessarily -- this calculator estimates a representative stopping time based on the selected Hazard Type for illustration purposes, but OSHA's actual standard requires stopping time to be determined by direct measurement on the specific machine (a stop-time analysis), not assumed from a generic category. Use this calculator to understand the relationship between stopping time and safe distance, then confirm with a measured value before finalizing a real guard installation.

Overall Compliant only shows compliant when both checks pass independently -- the opening must be small enough for its distance from the hazard (Opening Size Compliant), AND the guard must sit far enough away for the machine's stopping time (Distance Compliant). Passing one check while failing the other still leaves the guard non-compliant overall, since either gap alone could allow contact with the hazard.